Julie is at the store buying groceries. She needs to get a quart of orange juice and some peaches. The quart of orange juice costs $2.25 and the peaches are $0.75 each. The function f(x) = 0.75x + 2.25 represents Julie's expenses at the grocery store. What do the f(x) and the x represent?

A. f(x) represents the number of items purchased at the grocery store; x represents the number of peaches purchased
B. f(x) represents the total cost of the grocery bill; x represents the cost per peach
C. f(x) represents the number of items purchased at the grocery store; x represents the cost per peach
D. f(x) represents the total cost of the groceries; x represents the number of peaches purchased